Radiofrequency ablation using the second-generation temperature-controlled diamond tip system in paroxysmal and persistent atrial fibrillation: results from FASTR-AF.

BACKGROUND: Catheter ablation (CA) technology development reflects the need to improve the effectiveness of atrial fibrillation (AF) treatment. Recently, the DiamondTemp Ablation (DTA) RF generator software was updated with a more responsive power ramp. METHODS: DIAMOND FASTR-AF was a prospective, single-arm, multicenter trial. This study sought to characterize the performance of the updated DTA system for the treatment of patients with drug-refractory paroxysmal and persistent AF (PAF and PsAF). The primary effectiveness endpoint was freedom from atrial arrhythmia recurrence following a 90-day blanking period through 12 months, and the primary safety endpoint was a composite of serious adverse events. RESULTS: In total, 60 subjects (34 PAF and 26 PsAF) underwent CA at three centers. Patients were 71.7% male, (age 63.9 ± 10.2 years, with an AF diagnosis duration 3.1 ± 3.9 years and left atrial size 4.4 ± 0.8 cm). Pulmonary vein isolation-only ablation strategy was performed in 34 (56.7%) subjects. The procedural characteristics show a procedure time 90.8 ± 31.6 min, total RF time 14.7 ± 7.7 min, ablation duration 10.7 ± 3.6 s, and fluid infusion 284.7 ± 111.5 ml. The serious adverse event rate was 8.3% (5/60), 3 pulmonary edema and 2 extended hospitalizations. Freedom from atrial arrhythmia recurrence was achieved in 67.6% of subjects by 12 months. CONCLUSIONS: The updated DTA system demonstrated long-term safety and effectiveness through 12 months of post-ablation follow-up for patients with atrial fibrillation. Additionally, procedures were demonstrated to be highly efficient with short procedure times and low levels of fluid infusion. TRIAL REGISTRATION: Sponsored by Medtronic, Inc.; FASTR-AF ClinicalTrials.gov; NCT03626649.

Amiodarone versus placebo and class Ic drugs for cardioversion of recent-onset atrial fibrillation: a meta-analysis.

OBJECTIVES: This meta-analysis compared amiodarone with placebo and class Ic drugs for the cardioversion of recent-onset atrial fibrillation (AF), defined as lasting less than seven days. BACKGROUND: Despite the lack of trials that support its efficacy convincingly, amiodarone is widely used for conversion of recent-onset AF. METHODS: We searched Medline and EMBASE databases, as well as the Cochrane Controlled Trials Register for randomized trials on recent-onset AF comparing amiodarone to placebo or class Ic drugs. Data were combined according to a fixed effect model. The primary end point was the rate of conversion at 24 h. To study time-dependency of the drugs, efficacy at 1 to 2 h, 3 to 5 h, 6 to 8 h, and at 24 h was analyzed. RESULTS: We found six studies randomizing amiodarone versus placebo (595 patients) and seven studies versus class Ic drugs (579 patients). There was no significant difference between amiodarone and placebo at 1 to 2 h, but significant efficacy was found after 6 to 8 h (relative risk [RR] 1.23, p = 0.022) and at 24 h (RR 1.44, p < 0.001). Efficacy with amiodarone was inferior to class Ic drugs for up to 8 h (RR 0.67, p < 0.001) but no difference was seen at 24 h (RR 0.95, p = 0.50). There were no major adverse effects. CONCLUSIONS: Amiodarone is superior to placebo for cardioversion of AF, and even though the onset of conversion is delayed, its efficacy is similar at 24 h compared with class Ic drugs. These results favor amiodarone as a reasonable alternative for patients with recent AF in whom class Ic and other, more rapidly acting antiarrhythmic drugs cannot be used.